During a uni project we used the library FANN (fast artificial neural network) which was a nice library to work with back-propagation networks. Written in C. There seems to be a C++ wrapper too, haven't used it though.

ANN's and GA's: AI Techniques for Game Programming by Mat Buckland
General/Traditional Game AI (good stuff in here): Programming Game AI by Example by Mat Buckland (you might also see it as Game AI Programming by Example; same thing)
Information for both can be found at www.ai-junkie.com

Back in my humble community college days at Lehigh County Community College they used to have some AI conversations. Some people went over to MIT from there who qualified. So if you are really into AI and think you have a gift talk to a counselor who's in the Computer Science department about taking a few courses.